diff --git a/saxml/tools/offline_quantize.py b/saxml/tools/offline_quantize.py
index 43062570..5f9e22eb 100644
--- a/saxml/tools/offline_quantize.py
+++ b/saxml/tools/offline_quantize.py
@@ -56,6 +56,7 @@ def parse_known_args(argv):
       default='gptj',
       choices=[
           'gptj',
+          'gpt5b',
           'gemma2b',
           'gemma7b',
           'llama2-70b-weight-linear-only-int8',
@@ -74,6 +75,12 @@ def parse_known_args(argv):
       type=lambda x: bool(str(x).lower() == 'true'),
       help='Transpose embedding to reduce latency.',
   )
+  parser.add_argument(
+      '--transpose_cast_fp8',
+      default=False,
+      type=lambda x: bool(str(x).lower() == 'true'),
+      help='Transpose and cast fp8 weights.',
+  )
   parser.add_argument(
       '--quantize_embedding',
       default=False,
diff --git a/saxml/tools/quant_fn.py b/saxml/tools/quant_fn.py
index 54d77d42..d4fc7cf1 100644
--- a/saxml/tools/quant_fn.py
+++ b/saxml/tools/quant_fn.py
@@ -108,6 +108,10 @@ def process(self, action: quantization_actions.OptAction):
     if action.transpose_embedding:
       target_var = jnp.transpose(target_var)
 
+    if action.transpose_cast_fp8:
+      print(action.target_name)
+      target_var = jnp.transpose(target_var)
+
     if action.quantize_axis:
       quantize_axis = action.quantize_axis
       quantize_factor = action.quantize_factor
@@ -124,6 +128,8 @@ def process(self, action: quantization_actions.OptAction):
         p_value = action.optimization_p_value
         per_channel = True
 
+      print('here in quantize')
+      print(action.target_name)
       if self._symmetric:
         target_var, scale = quantization_configs.quantize_tensor(
             target_var,
diff --git a/saxml/tools/quantization_actions.py b/saxml/tools/quantization_actions.py
index 6d36be03..1c7adf13 100644
--- a/saxml/tools/quantization_actions.py
+++ b/saxml/tools/quantization_actions.py
@@ -36,6 +36,7 @@ class OptAction:
   quantize_axis: Optional[list[int]] = None
   quantize_factor: float = 1.0
   transpose_embedding: bool = False
+  transpose_cast_fp8: bool = False
   number_bit: int = 8
   pack_dim: int = 0
   use_optimization: bool = False
@@ -170,6 +171,7 @@ def _get_sub_layer(var_name: str) -> int:
       axis = None
       var_dtype = 'bfloat16'
       transpose_embedding = False
+      transpose_cast_fp8 = False
       quantize_factor = 1.0
       pack_dim = 0
       curr_config = config.get_quantize_axis_and_factor(source_name)
@@ -249,6 +251,21 @@ def _get_sub_layer(var_name: str) -> int:
           var_dtype = 'int8'
           axis = [1]  # we are quantizing embedding along the outer axis here
           quantize_factor = config.factor  # pytype: disable=attribute-error
+      
+      # fp8 weights cast and transpose
+ #     print(source_name)
+      if source_name in ('mdl_vars.params.lm.transformer.x_layers_0.ff_layer.ffn_layer1.linear.w',
+                         'mdl_vars.params.lm.transformer.x_layers_0.ff_layer.ffn_layer2.linear.w',
+                         'mdl_vars.params.lm.transformer.x_layers_1.ff_layer.ffn_layer2.linear.w'
+                         'mdl_vars.params.lm.transformer.x_layers_1.ff_layer.ffn_layer2.linear.w'
+                         'mdl_vars.params.lm.transformer.x_layers_2.ff_layer.ffn_layer2.linear.w'
+                         'mdl_vars.params.lm.transformer.x_layers_2.ff_layer.ffn_layer2.linear.w'
+                         'mdl_vars.params.lm.transformer.x_layers_3.ff_layer.ffn_layer2.linear.w'
+                         'mdl_vars.params.lm.transformer.x_layers_3.ff_layer.ffn_layer2.linear.w'):
+        if use_fp and number_bit == 8:
+          axis = [-1]
+          transpose_cast_fp8 = True
+          target_name = source_name
 
       # Setting quantization configs back to non-quantize when the source name
       # matches the skip pattern.
@@ -278,6 +295,7 @@ def _get_sub_layer(var_name: str) -> int:
               quantize_axis=axis,
               quantize_factor=quantize_factor,
               transpose_embedding=transpose_embedding,
+              transpose_cast_fp8=transpose_cast_fp8,
               number_bit=layer_wise_num_bits,
               pack_dim=pack_dim,
               use_optimization=use_optimization,
diff --git a/saxml/tools/quantization_configs.py b/saxml/tools/quantization_configs.py
index 55d28a99..06e34920 100644
--- a/saxml/tools/quantization_configs.py
+++ b/saxml/tools/quantization_configs.py
@@ -64,7 +64,16 @@ class QuantizationConfigsGPTJ(QuantizationConfigs):
       'self_attention.combined_qkv.w': ([1], factor, 1, -1),
       'self_attention.post.w': ([1, 2], factor, 0, -1),
   }
+class QuantizationConfigsGPT5B(QuantizationConfigs):
+  """Quantization config for GPT5B model."""
 
+  factor = 1.0
+  configs = {
+      'ff_layer.ffn_layer1.linear.w': ([0, 1], factor, 0, -1),
+      'ff_layer.ffn_layer2.linear.w': ([0, 1], factor, 0, -1),
+      'self_attention.combined_qkv.w': ([0, 1, 2, 3], factor, 1, -1),
+      'self_attention.post.w': ([0, 1, 2], factor, 0, -1),
+  }
 
 class QuantizationConfigsGPTJStacked(QuantizationConfigs):
   """Quantization config for GPTJ model."""
diff --git a/saxml/tools/quantization_provider.py b/saxml/tools/quantization_provider.py
index 73768459..79445e82 100644
--- a/saxml/tools/quantization_provider.py
+++ b/saxml/tools/quantization_provider.py
@@ -18,6 +18,7 @@
 
 NAME_TO_CONFIG = {
     'gptj': quantization_configs.QuantizationConfigsGPTJ(),
+    'gpt5b': quantization_configs.QuantizationConfigsGPT5B(),
     'gemma2b': quantization_configs.QuantizationConfigsGemma2B(),
     'gemma7b': quantization_configs.QuantizationConfigsGemma7B(),
     'llama2-70b-weight-linear-only-int8': (